摘要
为了提高电阻应变计测量精度,建立了“简支梁-过渡层-基底-栅丝”结构的3维有限元模型,利用数值模拟方法研究了敏感栅结构参数对测量精度的影响;提出横向效应长度比参数,统一了栅丝长度、间距、弯数3种结构参数,建立了测量误差与横向效应长度比的函数关系,基于此函数关系推导出结构参数优化公式,并利用优化公式完成了敏感栅结构参数组合设计。结果表明:栅丝直径越小,测量误差越小;栅丝长度、间距、弯数、长宽比存在最优值;测量误差与横向效应长度比成分段线性函数关系,且当横向效应长度比为6.15%时测量误差最小;利用函数关系式可以快速估算出给定敏感栅结构参数的应变计测量误差,估算结果与有限元计算结果的相对误差不超过4%;利用优化公式设计出的参数组合的测量误差不超过0.06%,且较单独优化的最优值参数组合的减小0.1%左右。
In order to improve the measurement accuracy of strain gauges,a three-dimensional finite element model consists of simply supported beam,transition layer,substrate and grid wire was established,and the influence of the structural parameters of the sensitive grid on measurement accuracy was numerical investigated.A parameter called transverse effect length ratio which covers the impact of grid length,spacing and number of bends was proposed.The correlation of measurement error and the lateral effect length ratio was established.Based on the correlation,the structural parameter optimization formula was derived to complete the design of the structural parameters combination of sensitive grid.The results show that the smaller the diameter of the grid wire,the smaller the measurement error.Measurement error orientated optimal values can be found individually for the length,spacing,number of bends and aspect ratio of the grid wire.The relationship between the measurement error and the lateral effect length ratio is piecewise linear,and the measurement error reaches minimum when the lateral effect length ratio is 6.15%.The measurement error of the strain gauge with a given set of structural parameters can be quickly estimated by using the relationship.The relative error between the result of estimation and the finite element calculation is less than 4%.The measurement error of the strain gauge using parameter combination derived from the optimization formula is not more than 0.06%,which is about 0.1%better than that derived from individually optimized parameter combination.
作者
王崇武
艾延廷
李成刚
宋瑞如
张岩松
王志
WANG Chong-wu;AI Yan-ting;LI Cheng-gang;SONG Rui-ru;ZHANG Yan-song;WANG Zhi(Liaoning Key Laboratory of Advanced Measurement and Test Technology for Aviation Propulsion System,Shenyang 110136,China;AECC Shenyang Engine Research Institute,Shenyang 110015,China)
出处
《航空发动机》
北大核心
2022年第5期167-172,共6页
Aeroengine
基金
国家自然科学基金(51975124、11702177)资助。
关键词
电阻应变计
敏感栅
测量精度
有限元法
长宽比
横向效应长度比
航空发动机
resistance strain gauges
sensitive grid
measurement accuracy
finite element method
aspect ratio
lateral effect length ratio
aeroengine
